6. Phytoliriomyza dumortierae Kato sp. nov.

Figs 10, 11

Material examined.

Holotype: Japan: 1♂ (MK-AG-246), Higashinakama, Sumiyo, Amami, Kagoshima Pref. (28.269613°N, 129.436562°E, 340 m asl), 21-II-2015 (as larva on Dumortiera hirsuta), emerged on 1-IV-2015, NSMT-I-Dip 31920. Paratypes: Japan: 1♂2♀ (MK-AG-a486, a487, a488), same data as holotype, emerged on 30-III-7-IV-2015, NSMT-I-Dip 31921-31923; 1♀ (MK-AG-267), Abe-toge, Aoi-ku, Shizuoka Pref., 1-V-2015 (as larva), emerged on 18-V-2015, NSMT-I-Dip 31924; 1♀ (MK-AG-241), Narutaki, Ichiu, Tsurugi, Tokushima Pref., 12-VI-2017 (as larva), emerged on 21-VI-2017, NSMT-I-Dip 31926; 1♀ (MK-AG-282), Isso, Yaku Is., Kumage, Kagoshima Pref., 29-III-2017 (as larva), emerged on 2-V-2017, NSMT-I-Dip 31927; 1♀ (MK-AG-250), Nagakumo-toge, Tatsugo, Oshima, Kagoshima Pref., 23-II-2016 (as larva), emerged on 25-III-2015, NSMT-I-Dip 31928.

Other material.

Japan: 5♂4♀, Abe-toge, Aoi-ku, Shizuoka Pref., 5-I-2015 (as larva), emerged on 18-V-2016; 2♂3♀, Tango-kanzaki, Maizuru, Kyoto Pref., 19-V-2021 (as larva), emerged on 30-V-5-VI-2021; 1♂1♀, Tategasaki, Kumano, Mie Pref., 23-IV-2021 (as larva), emerged on 11-V-2021; 3♀, Gakuen-ji, Bessho, Izumo, Shimane Pref., 31-III-2015 (as larva), emerged on 9-V-2015; 3♂1♀, Tazukawa-keikoku, Katsuura, Tokushima Pref., 30-III-2021 (as larva), emerged on 11-20-V-2021; 3♂4♀, Narutaki, Ichiu, Tsurugi, Tokushima Pref., 12-VI-2017 (as larva), emerged on 17-21-VI-2017; 1♀, Tashiro, Kinko, Kimotsuki, Kagoshima Pref., 22-III-2015 (as larva), emerged on 1-V-2015; 1♂1♀, Isso, Yaku Is., Kumage, Kagoshima Pref., 11-III-2016 (as larva), emerged on 617-19-IV-2016; 11♂14♀, Higashinakama, Sumiyo, Amami, Kagoshima Pref., 21-II-2015 (as larva), emerged on 30-III-8-IV-2015.

Diagnosis.

A large dark species (wing length 1.9-2.2 mm) having subshiny dark brown scutum, brownish yellow scutellum, black 1st flagellomere, dark maxillary palpus, dark halteres, and dark gray legs. Male epandrium inner-laterally with an incomplete comb comprising three short, fused, tubercle-like setae medially. Larva mines the thallus of Dumortiera hirsuta .

Description.

Adult male (Fig. 10A-D).

Head: Head largely light yellow; ocellar triangle yellow but ocellar tubercle dark brown; front-orbital plate brown; back of head brown above foramen excluding margin (Fig. 10C). Antenna porrect, first flagellomere black, pedicel and scape brown. Arista subbasal, pubescent. Face, gena, parafacial and postgena light yellow. Proboscis normal, yellow; palpus brown, cylindrical. Chaetotaxy: Front orbitals three pairs; one ori directed inward; two ors directed upward (Fig. 10B). Orbital setulae minute and erect, in a single row.

Thorax: Thorax subshiny. Scutum dark brown with a pair of terminal yellow patches adjoining scutellum (Fig. 10D). Scutellum yellow with lateral corner narrowly brown. Mediotergite, katatergite and anatergite dark brown. Pleuron yellow, lower half of anepisternum and anepimeron brown, meron and katepisternum brown (Fig. 10B). Haltere light yellow. Calypter margin and hairs gray. Leg segments brown; tibia and tarsus dark brown. Chaetotaxy: Scutum with 1+3 dorsocentrals, shortened anteriorly. Acrostichal setulae seven or eight pairs in two rows (Fig. 10D). Wing: Wing length 1.9 mm, costa reaching M1 (Fig. 10A). Length of ultimate section of vein M4 divided by penultimate section 1.2.

Abdomen: Abdomen dorsally subshiny brown (Fig. 10A). Genitalia: (Fig. 10F-L) Epandrium dark brown rounded apically, onion-shaped in lateral view (Fig. 10G); inner-anterior margin with two stout tubercle-like setae, and inner-lateral margin with an incomplete comb comprising three short, fused, tubercle-like setae medially (Fig. 10K, L). Surstylus with a row of seven or eight strong setae apically and one or two stout tubercle-like setae posteriorly. Subepandrial sclerite with one pair of long, ventrally directed arms; distal end flattened and expanded (Fig. 10F). Hypandrium sclerotized along outer margin (Fig. 10F). Postgonite bare and goose barnacle-shaped with a pointed apex (Fig. 10J). Phallophorus articulated with phallapodeme, fused to epiphallus (Fig. 10H, J). Basiphallus consisting of a pair of asymmetric dark narrow plate-like sclerites; both protruding ventrally (Fig. 10F-H, J). Hypophallus broad and membranous with lateral margin sclerotized, medially with a pair of short converging sclerites (Fig. 10H, J). Paraphallus narrow, membranous and distally pointed, with distal tip pigmented (Fig. 10F-H, J). Mesophallus dark, turgid, widest subbasally, as long as distiphallus (Fig. 10H). Distiphallus comprising one pair of stout tubules; basal 1/3 composed of dark sclerite basally and weaker medial region; distal 2/3 dark, claviform, tip rounded (Fig. 10H). Ejaculatory apodeme fan-shaped with marginal pale area and broad stalk; base dark and wide to one side; sperm pump clear (Fig. 10I).

Female (Fig. 10E). Similar to male, but slightly larger. Wing length 2.2 mm. Postabdomen: (Fig. 11A, B) Oviscape dark brown sparsely setigerous (Fig. 11A). Tergite 10 trifurcate, laterally uniting narrow pleural sclerites (Fig. 11B). Each cercus with two stout, apical, trichoid sensilla, 1/3 length of cercus. Spermathecae semi-orbicular, with truncate proximal ends (Fig. 11A).

Variation.

The color of frons and scutellum varies from yellow to brownish yellow in some localities.

Etymology.

The specific name refers to its host plant genus Dumortiera .

Japanese name.

Zangetsu-kezenigoke-hamoguribae.

Host plant.

Dumortiera hirsuta ( Dumortieraceae).

Mine.

(Fig. 11C, E, F, H, I) Larvae construct linear mines in the midrib of the thallus in early instars, and in the last instar construct radiate or blotch mines by coming out from the midrib, and pupate in the mines.

Biological notes.

The main habitats of this species are along streams in warm temperate evergreen forests (Fig. 11D, G). Our rearing records suggest that this species is univoltine, and that adults emerge from overwintered pupae in spring.

Distribution.

Japan: Honshu, Shikoku, Kyushu, Yaku Island and Amami-oshima Island (Fig. 12).

Remarks.

This species resembles P. wiesnerellae in coloration of head, thorax, abdomen, and legs; it is distinguished from the latter by the pleuron with the lower half darkened (pleuron almost wholly yellow in P. wiesnerellae). The great morphological difference in male genitalia suggests that these two species are not closely related.